The present invention relates to a competition or cruiser sail-boat comprising a hull which is closed by a deck and in which the lower end of a mast carrying the sails is implanted.
In recent years there has been a substantial development in yachting and many individuals have already acquired or envisage acquiring a sail-boat.
The current yachting fleet is principally constituted, in particular in the field of medium-size craft, by mono-hull habitable sail-boats which are relatively inexpensive and largely satisfactory from the point of view of comfort and the possibilities of interior fitting-out.
The rigging of these sail-boats is usually constituted by a mast and shrouds, the role of which is to support and strengthen the mast.
The appearance of sail-boats of which the hull is no longer made of wood but of materials known as composites, in particular laminated plastics (epoxy carbon fibre), has led to sail-boats being proposed to the public in which the mast is implanted directly in the hull, which enables the side shrouds to be dispensed with and therefore the structure of the boat to be substantially simplified.
However, the consequence of such a design is a substantial increase in the weight of the rigging, given that the mast must thus be substantially heavier with a very high centre of gravity; this has a detrimental effect and greatly impairs the speed of the boat, in particular when the wind is strong.
This situation is more especially disadvantageous as more and more yachtsmen, influenced especially by the great transoceanic races, are looking for sports performance and therefore wish to acquire a sail-boat which is the fastest possible.
The object of the present invention is to propose a competition or cruiser sail-boat having an implanted mast, of the above-mentioned type, which is capable of meeting those requirements.
Such a sail-boat is characterised in that the mast is a tilting mast which is free from side shrouds and which is mounted to pivot, especially on bearings, about at least one substantially horizontal axis, that axis coinciding with the longitudinal axis of the hull; owing to this capacity for port-starboard tilting, regardless of the weather conditions, the centre of gravity of the mast can be placed in the wind, at the centre of rotation of the sail-boat, and the plane of the sails can be placed perpendicular to the airstreams.
According to a preferred feature of the invention, the mast is a turning and tilting mast mounted to pivot about three axes which are perpendicular to one another, namely an upright axis, the port-starboard tilting axis and a substantially horizontal axis perpendicular to the tilting axis, and can therefore be oriented in all directions.
According to the invention, such a mast may advantageously be mounted on a bearing of the ball-and-socket joint type secured at the level of the deck of the sail-boat; at the same time, its foot can slide on a rail, preferably of carbon fibre, inserted at the bottom of the hull.
This configuration on the one hand enables the righting moment of the sail-boat to be increased, as a result of the displacement of the centre of gravity of the mast into the wind thereof and, on the other hand, enables the aerodynamic propulsive force to be increased given that the mast can be oriented perpendicularly to the airstreams, and even enables a slight lifting effect to be developed. At the same time, there is a reduction in the drag, bearing in mind the absence of shrouds.
According to another feature of the invention, the mast cooperates, by way of its lower end, with manoeuvring members enabling it to be oriented and locked in a determined position.
Such adjustment can be carried out manually by means of control levers made available to the helmsman.
It would also be possible to provide for automatic control of the orientation of the mast from devices for detecting the position of the sail-boat which cooperate with an electronic servo-control system known per se.
It should be noted that, in the course of sailing, the forces exerted on the mast are absorbed by the bearing having a ball-and-socket joint and by the manoeuvring members.
According to a non-limiting feature of the invention, the mast can, respectively, tilt by an angle of xc2x145xc2x0 about a substantially horizontal axis coinciding with the longitudinal axis of the hull, and, optionally, about an axis which is also substantially horizontal and which is perpendicular to the longitudinal axis.
According to another non-limiting feature of the invention, the mast can tilt by an angle which may exceed xc2x190xc2x0 about a substantially vertical axis perpendicular to the longitudinal axis of the hull.
It has been established that this ability of the mast to tilt about each of its three pivoting axes is sufficient for it to adapt to all sailing conditions (listing, pitching or rolling).
According to another feature of the invention, the mast has a cross-section in the shape of a wing; such a configuration is particularly advantageous from an aerodynamic point of view, given that it brings about a substantial reduction in the drag or resistance to advance, and, at the same time, from a structural point of view, in respect of the rigidity of the mast; the mainsail is then mounted in such a manner that it stresses the mast according to its greatest inertia.
It should be noted that, according to the invention, the lateral rigidity of the mast is ensured exclusively by the mast, in particular if it has a wing-shaped profile. The longitudinal rigidity can, for its part, be xe2x80x9cstrengthenedxe2x80x9d by the halyards of the sails returned to the rear or a longitudinal front shroud having a post (stay), which shroud is stiffened by a runner and tackle if this stay is used as a support for the hoist of a head sail, for example.